Endpoint detection device for realizing real-time control of plasma reactor, plasma reactor with endpoint detection device, and endpoint detection method

1. An endpoint detection device comprising: an Optical Emission Spectrometer (OES) data operation unit for processing reference OES data by normalization and Principal Component Analysis (PCA), outputting linear reference loading vectors and rate values of reference principal components, and outputting reference ranking values on the basis of the linear reference loading vectors; a data selector for first selecting part of the linear reference loading vectors on the basis of the rate values of the reference principal components, selecting part of the reference OES data or selecting part of process OES data on the basis of the reference ranking values, and second selecting part of the first selected linear reference loading vectors on the basis of the reference ranking values; a product generator for outputting at least one reference product value on the basis of the first selected linear reference loading vectors and the reference OES data; a Support Vector Machine (SVM) for performing regression on the basis of the selected reference OES data and the at least one reference product value, generating nonlinear reference loading vectors, and periodically outputting a prediction product value on the basis of the second selected linear reference loading vectors, the nonlinear reference loading vectors, and the selected process OES data; and an endpoint determiner for detecting a process wafer etch or deposition endpoint on the basis of the periodically received prediction product value and outputting a detection signal, wherein first lights of a whole wavelength emitted from the inside of a plasma reaction chamber are converted into the reference OES data by a spectrometer during a reference wafer etch or deposition process and second lights of a whole wavelength emitted from the inside of the plasma reaction chamber are converted into the process OES data by the spectrometer during a process wafer etch or deposition process executed after the reference wafer etch or deposition process, wherein the reference ranking values represent a ranking for the intensity of the first lights of the whole wavelength, and wherein the linear reference loading vectors each correspond to one-dimensional function values expressed by the reference OES data and the nonlinear reference loading vectors each correspond to S-dimensional, wherein S: integer larger than 1, function values expressed by the selected process OES data.

2. The device of claim 1 , further comprising: an abnormality diagnosis unit for diagnosing normality or abnormality of a currently etched or deposited process wafer depending on whether a mean deviation value is comprised within a stable range determined by an average value and controlling a display unit to visually display the normality or abnormality of the process wafer, wherein the OES data operation unit processes the process OES data by normalization and PCA, further outputs linear process loading vectors and rate values of process principal components, and further outputs process ranking values representing a ranking for the intensity of the second lights of the whole wavelength on the basis of the linear process loading vectors, wherein the data selector selects part of the linear process loading vectors on the basis of the rate values of the process principal components, wherein the product generator further outputs an actual product value on the basis of the selected linear process loading vectors and the process OES data, wherein whenever the process wafer etch or deposition process is executed, the SVM accumulates each of the actual product values received from the product generator and further calculates the average value and the mean deviation value for the accumulated actual product values, and wherein the linear process loading vectors each correspond to one-dimensional function values expressed by the process OES data.

3. The device of claim 2 , wherein when the number of times of execution of the process wafer etch or deposition process reaches the preset number of times, the data selector outputs an update request signal and further selects part of the process OES data and part of the selected linear process loading vectors on the basis of the process ranking values, the SVM performs regression on the basis of the actual product value generated by the product generator and the selected process OES data during a current process wafer etch or deposition process in response to the update request signal, generates nonlinear process loading vectors, and uses the further selected linear process loading vectors and the nonlinear process loading vectors to generate prediction product values from a time of a subsequent process wafer etch or deposition process up to a time of a process wafer etch or deposition process before execution of a subsequent regression operation, and the nonlinear reference loading vectors each correspond to S-dimensional (S: integer larger than 1) function values expressed by the selected process OES data.

4. The device of claim 2 , wherein the OES data operation unit comprises: a normalization processor for normalizing the reference OES data and outputting reference average scaling data or normalizing the process OES data and outputting process average scaling data; a PCA processor for processing the reference average scaling data by PCA and outputting the linear reference loading vectors and the rate values of the reference principal components or processing the process average scaling data by PCA and outputting the linear process loading vectors and the rate values of the process principal components; and a ranking determiner for outputting the reference ranking values on the basis of the linear reference loading vectors or outputting the process ranking values on the basis of the linear process loading vectors.

5. The device of claim 4 , wherein the OES data operation unit further comprises: a storage unit for storing the linear reference loading vectors and the rate values of the reference principal components or the linear process loading vectors and the rate values of the process principal components received from the PCA processor and storing the reference ranking values or the process ranking values received from the ranking determiner.

6. The device of claim 2 , wherein an upper limit value of the stable range is determined by a sum of the average value and a deviation value, a lower limit value of the stable range is determined by a difference between the average value and the deviation value, and the deviation value is preset to the abnormality diagnosis unit.

7. A plasma reactor comprising: a plasma reaction chamber which a reference wafer or a process wafer is mounted inside; a spectrometer for converting first lights of a whole wavelength emitted from the inside of the plasma reaction chamber into reference OES data during a reference wafer etch or deposition process or converting second lights of a whole wavelength emitted from the inside of the plasma reaction chamber into process OES data during a process wafer etch or deposition process executed after the reference wafer etch or deposition process; an optical fiber cable for collecting the first or second lights of the whole wavelength emitted from the inside of the plasma reaction chamber through a window provided at an outer wall of the plasma reaction chamber and forwarding the collected lights to the spectrometer during the reference wafer or process wafer etch or deposition process; an endpoint detection device for detecting a process wafer etch or deposition endpoint and outputting a detection signal on the basis of the reference OES data and the process OES data; and a plasma reaction controller for controlling an etch or deposition condition within the plasma reaction chamber in response to the detection signal, the endpoint detection device comprising: an OES data operation unit for processing the reference OES data by normalization and PCA, outputting linear reference loading vectors and rate values of reference principal components, and outputting reference ranking values on the basis of the linear reference loading vectors; a data selector for first selecting part of the linear reference loading vectors on the basis of the rate values of the reference principal components, selecting part of the reference OES data or selecting part of the process OES data on the basis of the reference ranking values, and second selecting part of the first selected linear reference loading vectors on the basis of the reference ranking values; a product generator for outputting at least one reference product value on the basis of the first selected linear reference loading vectors and the reference OES data; an SVM for performing regression on the basis of the selected reference OES data and the at least one reference product value, generating nonlinear reference loading vectors, and periodically outputting a prediction product value on the basis of the second selected linear reference loading vectors, the nonlinear reference loading vectors, and the selected process OES data; and an endpoint determiner for detecting a process wafer etch or deposition endpoint on the basis of the periodically received prediction product value and outputting a detection signal, wherein the reference ranking values represent a ranking for the intensity of the first lights of the whole wavelength, and wherein the linear reference loading vectors each correspond to one-dimensional function values expressed by the reference OES data and the nonlinear reference loading vectors each correspond to S-dimensional, wherein S: integer larger than 1, function values expressed by the selected process OES data.

8. The plasma reactor of claim 7 , further comprising: an abnormality diagnosis unit for diagnosing normality or abnormality of a currently etched or deposited process wafer depending on whether a mean deviation value is comprised within a stable range determined by an average value and controlling a display unit to visually display the normality or abnormality of the process wafer, wherein the OES data operation unit processes the process OES data by normalization and PCA, further outputs linear process loading vectors and rate values of process principal components, and further outputs process ranking values representing a ranking for the intensity of the second lights of the whole wavelength on the basis of the linear process loading vectors, wherein the data selector selects part of the linear process loading vectors on the basis of the rate values of the process principal components, wherein the product generator further outputs an actual product value on the basis of the selected linear process loading vectors and the process OES data, wherein whenever the process wafer etch or deposition process is executed, the SVM accumulates each of the actual product values received from the product generator and further calculates the average value and the mean deviation value for the accumulated actual product values, and wherein the linear process loading vectors each correspond to one-dimensional function values expressed by the process OES data.

9. The plasma reactor of claim 8 , wherein when the number of times of execution of the process wafer etch or deposition process reaches the preset number of times, the data selector outputs an update request signal and further selects part of the process OES data and part of the selected linear process loading vectors on the basis of the process ranking values, the SVM performs regression on the basis of the actual product value generated by the product generator and the selected process OES data during a current process wafer etch or deposition process in response to the update request signal, generates nonlinear process loading vectors, and uses the further selected linear process loading vectors and the nonlinear process loading vectors to generate prediction product values from a time of a subsequent process wafer etch or deposition process up to a time of a process wafer etch or deposition process before execution of a subsequent regression operation, and the nonlinear reference loading vectors each correspond to S-dimensional (S: integer larger than 1) function values expressed by the selected process OES data.

10. The plasma reactor of claim 8 , wherein the OES data operation unit comprises: a normalization processor for normalizing the reference OES data and outputting reference average scaling data or normalizing the process OES data and outputting process average scaling data; a PCA processor for processing the reference average scaling data by PCA and outputting the linear reference loading vectors and the rate values of the reference principal components or processing the process average scaling data by PCA and outputting the linear process loading vectors and the rate values of the process principal components; and a ranking determiner for outputting the reference ranking values on the basis of the linear reference loading vectors or outputting the process ranking values on the basis of the linear process loading vectors.

11. The plasmas reactor of claim 10 , wherein the OES data operation unit further comprises: a storage unit for storing the linear reference loading vectors and the rate values of the reference principal components or the linear process loading vectors and the rate values of the process principal components received from the PCA processor and storing the reference ranking values or the process ranking values received from the ranking determiner.

12. An endpoint detection device comprising: a data selector for setting a data selection range and outputting an operation control signal in response to a data selection signal, selecting part of reference OES data on the basis of the data selection range during a reference wafer etch or deposition process, and selecting part of process OES data on the basis of the data selection range during a process wafer etch or deposition process; an OES data operation unit for processing the selected reference OES data by normalization and PCA and outputting linear reference loading vectors in response to the operation control signal; a product generator for periodically outputting a prediction product value on the basis of the linear reference loading vectors and the selected process OES data; and an endpoint determiner for detecting a process wafer etch or deposition endpoint and outputting a detection signal on the basis of the periodically received prediction product value, wherein first lights of a whole wavelength emitted from the inside of a plasma reaction chamber are converted into the reference OES data by a spectrometer during a reference wafer etch or deposition process and second lights of a whole wavelength emitted from the inside of the plasma reaction chamber are converted into the process OES data by the spectrometer during a process wafer etch or deposition process executed after the reference wafer etch or deposition process, and wherein the linear reference loading vectors each correspond to one-dimensional function values expressed by the reference OES data.

13. The device of claim 12 , wherein the data selector changes and sets the data selection range and outputs the operation control signal whenever further receiving the data selection signal, wherein the OES data operation unit processes, by normalization and PCA, process OES data selected on the basis of the changed data selection range by the data selector and outputs linear process loading vectors during a current process wafer etch or deposition process in response to the operation control signal, and wherein the product generator uses the linear process loading vectors to generate prediction product values from a time of a subsequent process wafer etch or deposition process up to a time of a process wafer etch or deposition process before the OES data operation unit executes a subsequent normalization and PCA process operation.

14. The device of claim 13 , wherein the OES data operation unit comprises: a normalization processor for normalizing the reference OES data and outputting reference average scaling data or normalizing the process OES data and outputting process average scaling data, in response to the operation control signal; and a PCA processor for processing the reference average scaling data by PCA and outputting the linear reference loading vectors or processing the process average scaling data by PCA and outputting the linear process loading vectors.

15. The device of claim 14 , wherein the OES data operation unit further comprises: a storage unit for storing the linear reference loading vectors or the linear process loading vectors received from the PCA processor in response to the operation control signal.

16. The device of claim 13 , wherein the data selection range is any one or more of at least one set wavelength band range, at least one set time range, and a wavelength band range of lights emitted by at least one set element.

17. A plasma reactor comprising: a plasma reaction chamber which a reference wafer or a process wafer is mounted inside; a spectrometer for converting first lights of a whole wavelength emitted from the inside of the plasma reaction chamber into reference OES data during a reference wafer etch or deposition process or converting second lights of a whole wavelength emitted from the inside of the plasma reaction chamber into process OES data during a process wafer etch or deposition process executed after the reference wafer etch or deposition process; an optical fiber cable for collecting the first or second lights of the whole wavelength emitted from the inside of the plasma reaction chamber through a window provided at an outer wall of the plasma reaction chamber and forwarding the collected lights to the spectrometer during the reference wafer or process wafer etch or deposition process; an endpoint detection device for detecting a process wafer etch or deposition endpoint and outputting a detection signal on the basis of the reference OES data and the process OES data; and a plasma reaction controller for controlling an etch or deposition condition within the plasma reaction chamber in response to the detection signal, the endpoint detection device comprising: a data selector for setting a data selection range and outputting an operation control signal in response to a data selection signal, selecting part of reference OES data on the basis of the data selection range during the reference wafer etch or deposition process, and selecting part of process OES data on the basis of the data selection range during the process wafer etch or deposition process; an OES data operation unit for processing the selected reference OES data by normalization and PCA and outputting linear reference loading vectors in response to the operation control signal; a product generator for periodically outputting a prediction product value on the basis of the linear reference loading vectors and the selected process OES data; and an endpoint determiner for detecting a process wafer etch or deposition endpoint and outputting a detection signal on the basis of the periodically received prediction product value, wherein the linear reference loading vectors each correspond to one-dimensional function values expressed by the reference OES data.

18. The plasma reactor of claim 17 , wherein the data selector changes and sets the data selection range and outputs the operation control signal whenever further receiving the data selection signal, wherein the OES data operation unit processes, by normalization and PCA, process OES data selected on the basis of the changed data selection range by the data selector and outputs linear process loading vectors during a current process wafer etch or deposition process in response to the operation control signal, and wherein the product generator uses the linear process loading vectors to generate prediction product values from a time of a subsequent process wafer etch or deposition process up to a time of a process wafer etch or deposition process before the OES data operation unit executes a subsequent normalization and PCA process operation.

19. The plasma reactor of claim 17 , further comprising: a display unit for displaying the reference OES data or the process OES data in a three-dimensional graphic picture; and an input unit comprising a plurality of keys and outputting the data selection signal in response to pressing the plurality of keys.